Molar ratios synthesis

Figure 1. Ethylene glycol from synthesis gas via ruthenium rhodium bimetallic melt catalysis. Effect of Rh Ru molar ratios. Synthesis conditions as per Table II. Effect of varying [Rh],0 effect of varying [Ru],...

The Stainicaibon process is described in Figures 3—7. The synthesis section of the plant consists of the reactor, stripper, high pressure carbamate condenser, and a high pressure reactor off-gas scmbber. In order to obtain a maximum urea yield pet pass through the reactor, a pressure of 14 MPa (140 bar) and a 2.95/1 NH —CO2 molar ratio is maintained. The reactor effluent is distributed over the stripper tubes (falling-film type shell and tube exchanger) and contacted by the CO2, countercurrendy. This causes the partial NH pressure to decrease and the carbamate to decompose. 

Reaction with Sulfur Nucleophiles, Because sulfai is highly nucleophilic, reactions of aziridines with sulfur nucleophiles generally proceed rapidly (111) and with good yields. The reaction of hydrogen sulfide [7783-06S-J with ethyleneimine yields cysteamine [60-23-1] (2-mercaptoethylamine) or bis(2-aminoethyl)sulfide [871-76-1] (2,112) depending on the molar ratio of the reactants. The use of NaHS for the synthesis of cysteamine has also been described (113). 

Ammonia Synthesis and Recovery. The purified synthesis gas consists of hydrogen and nitrogen in about 3 1 molar ratio, having residual inerts (CH Ar, sometimes He). The fresh make-up gas is mixed with the loop recycle and compressed to synthesis pressures. AH modern synthesis loops recycle the unreacted gases because of equiUbrium limitations to attain high overall conversions. The loop configurations differ in terms of the pressure used and the point at which ammonia is recovered. 

Process Description. Reactors used in the vapor-phase synthesis of thiophene and aLkylthiophenes are all multitubular, fixed-bed catalytic reactors operating at atmospheric pressure, or up to 10 kPa and with hot-air circulation on the shell, or salt bath heating, maintaining reaction temperatures in the range of 400—500°C. The feedstocks, in the appropriate molar ratio, are vaporized and passed through the catalyst bed. Condensation gives the cmde product mixture noncondensable vapors are vented to the incinerator. 

In addition to the normal methylene linkage formation involved in polymerization with both resoles and novolaes, other, usually less desirable, eondensation by-products are also seen in novolac synthesis. Among these are benzodioxanes and dibenzyl ethers. The reaction pH has significant effect on the relative amounts produced. Fig. 15 shows typical structures for these by-products. When such byproducts are present, the meaning of the molar ratio changes and variability with respect to molecular weight development, glass transition point, and solubility may be seen. They also lead to poor raw material utilization. 

Linear step-growth polymerizations require exceptionally pure monomers in order to ensure 1 1 stoichiometry for mutually reactive functional groups. For example, the synthesis of high-molecular-weight polyamides requires a 1 1 molar ratio of a dicarboxylic acid and a diamine. In many commercial processes, the polymerization process is designed to ensure perfect functional group stoichiometry. For example, commercial polyesterification processes often utilize dimethyl terephthalate (DMT) in the presence of excess ethylene glycol (EG) to form the stoichiometric precursor bis(hydroxyethyl)terephthalate (BHET) in situ. 

There are some means for synthesis of defined primary or secondary esters. Monoester salts of phosphoric acid, for instance, are prepared by addition of alcohol or ethoxylated alcohol, alkali fluoride, and pyrophosphoryl chloride (C12P0)20 in a molar ratio of 0.9-1.5 0.05-1 1.0 at -50 to +10°C and hydrolysis of the Cl-containing intermediates with base. Thus, 32.3 g (C12P0)20 was treated at -50°C with 23.9 g lauryl alcohol in the presence of 0.7 g KF and the mixture was slowly warmed to room temperature and hydrolyzed with H20 and 40% NaOH to give 83% sodium monolauryl phosphate. The monoester salts showed comparable or better washing and foaming efficiency than a commercial product [12]. 

Deng, D. W. Qin, Y. B. Yang, X. Yu, J. S. and Pan, Y. (2006). The selective synthesis of water-soluble highly luminescent CdTe nanoparticles and nanorods The influence of precursor Cd/Te molar ratio.. Cryst. Growth, 296,141-149. 

The mechanical properties, degradation, and surface characteristics of poly(diol citrates) could be controlled by choosing different diols and by controUing synthesis conditions such as cross-linking temperature and time, vacuum, and initial monomer molar ratio. 

The final structure of resins produced depends on the reaction condition. Formaldehyde to phenol (F/P) and hydroxyl to phenol (OH/P) molar ratios as well as ruction temperahne were the most important parameters in synthesis of resols. In this study, the effect of F/P and OH/P wt%, and reaction temperature on the chemical structure (mono-, di- and trisubstitution of methyrol group, methylene bridge, phenolic hemiformals, etc.) was studied utilizing a two-level full factorial experimental design. The result obtained may be applied to control the physical and chemical properties of pre-polymer. 

A two level full factorial experimental design with three variables, F/P molar ratio, OH/P wt %, and reaction temperature was implemented to analyses the effect of variables on the synthesis reaction of PF resol resin. Based on the composition of 16 components of 10 samples, the effect of three independent variables on the chemical structure was anal3 ed by using 3 way ANOVA of SPSS. The present study provides that experimental design is a very valuable and capable tool for evaluating multiple variables in resin production. 

Figure 7 illustrates the use of HPGPC to aid a resin chemist in developing an in-house isocyanate crosslinker for a powder coating system. Isocyanate crosslinker X-02 gave desired properties and is considered the standard. At the early stage of the development, resin X-03 was initially made. By changing the types of reactants, molar ratio of reactants and reaction conditions, resin X-36 was the next iteration in the resin synthesis process. Finally, X-36 was fine-tuned to produce X-38 which matched X-02 in both its chemical reaction properties and its MWD. 

To pursue the development of environmentally benign synthesis routes for ionic liquids, the alkylation step (Menschutkin reaction) was investigated by the authors in detail. The preparation of the ionic liquid 1-hexyl-3-methyhmidazohum chloride ([CeMlMJCl) was taken as a representative experiment (Scheme 7.2). The process parameters temperature (T = 70-100°C), solvent (ethanol, xylene, cyclohexane, n-heptane, solvent free), concentration of the N-base (c = 1.6-6.7 M), molar ratio n n = 1 0.5-1 4) and reaction time (f = 10-144 h) were investigated. In addition, the N-base was altered in order to proof the transferability of the reaction parameters. 

The alkaline EG synthesis method has been successfully applied to the preparation of unprotected bimetallic nanocluster colloids with controllable composition. Figure 3 shows the TEM image of bimetallic Pt/Ru nanoclusters (Pt/Ru molar ratio = 1 1.9, total metal concentration 1.85 g/1) with an average particle size of 1.9 nm and a size distribution from 1.4 to 2.4 nm. XRD pattern of the bimetallic nanoclusters is shown in Figure... 

The investigation of the chemical modification of dextran to determine the importance of various reaction parameters that may eventually allow the controlled synthesis of dextran-modified materials has began. The initial parameter chosen was reactant molar ratio, since this reaction variable has previously been found to greatly influence other interfacial condensations. Phase transfer catalysts, PTC s, have been successfully employed in the synthesis of various metal-containing polyethers and polyamines (for instance 26). Thus, the effect of various PTC s was also studied as a function of reactant molar ratio. 

The first stage of the process is a hydroformylation (oxo) reaction from which the main product is n-butyraldehyde. The feeds to this reactor are synthesis gas (CO/H2 mixture) and propylene in the molar ratio 2 1, and the recycled products of isobutyraldehyde cracking. The reactor operates at 130°C and 350 bar, using cobalt carbonyl as catalyst in solution. The main reaction products are n- and isobutyraldehyde in the ratio of 4 1, the former being the required product for subsequent conversion to 2-ethylhexanol. In addition, 3 per cent of the propylene feed is converted to propane whilst some does not react. 

Synthesis. Bis(2-hydroxyethyl)phosphite was synthesized by adopting the procedures described by Borisov and Troev (6). Briefly, a molar ratio of 4 1 of ethylene glycol (73 mL 1.3 mole) to diethylphosphite (43 mL 0.33 mole) was placed in a round bottom flask equipped with a reflux condenser and a thermometer. A two mL fresh solution of sodium methoxide was added dropwise through a dropping... 

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